Swing-prams grinder



1929- A. G. BELDEN ET AL SWING FRAME GRINDER Filed June 29, 1926 w Dwwlfww Alber'T G. Beiden In Q9 Howard W. Dunbar Wilneww W m. m

w up .WN P nu .v ML m Patented Get. 29, 1929 E A T E T GFFECE ALBERT G. BELDEN, HOWARD W. DUITBAR, AHD CARL FLYGAlR-E, OF WORCESTER,

MASSACHUSETTS, ASSIGNORS TO HGZLT 0N COMPANY, OF WORCESTER, MASSACHU- SETTS, A CORPORATIGN OF MASSACHUSETTS SWING-FRAME GRINDER Application filed June 2%), 1326.

This invention relates to grinding machines and more particularly to a swing frame grinder adapted for use in the grinding of billets, snagging of large castings and the like.

Heretofore, the swing frame grinders as developed and used have had various ob jectionable features. In most of the prior constructions the grinding wheel has been mounted with direct driving connections to a motor, or in some cases to an overhead countershaft, so that any vibration due to the grinding wheel striking projections on the rough surface of the casting being ground or to any out of balance condition of the grinding wheel has been transmitted to the operator. Production per operator is low due to continual vibrations and shocks which quickly tire him and thereby reduce his efficiency. Heretofore in the swing frame grinders the wheel wear has been excessive in relation to the amount of material removed by the grinding wheel. By experimental tests, the grinding wheels in use where rigid bearings are provided for the grinding wheel spindle on swing frame grinders have shown an average wear of three to four cubic inches of wheel per pound of metal removed. This is due largely to the swing "o n "or being swung over tl: ro .gh r .c 1., n snagged or cleaned and the proj ,ctions there on tearing out and ripping off the outer layer of abrasive grains and thereby rapidly reducing the size of the wheel.

It'is an object of the invention to overcome these difliculties and to provide a constructionin which the swing frame may be re. f balanced so as to reduce the fatigue of the operator to a minimum.

It is a further object of the invention to provide a yieldable mounting for the grind ing wheel spindle so that the grinding wheel when rotated will automatically be thrown into running balance.

In most of the mechanisms in use, a motor is fixed upon the frame to drive the grinding wheel and provision is not made for an adjustable mounting for the motor wher by any style or type of motor may be utilized and readily put into balance.

Serial No. 119,418.

It is a further object of the invention to provlde a construction whereby any motor of a standard make may be utilized and secured to a mounting plate which is adjustable transversely on the frame so that the swing frame may be balanced laterally as well as longitudinally of the frame by positioning the motor mounting relative to the end portion of the frame and by shifting the fulcrum point longitudinally of the frame.

Further objects of the invention will be apparent from the following disclosures.

Referring more particularly to the drawings in which like reference numerals indicate like parts:

Figure 1 is a perspective view of the swing frame grinder having a portion broken away;

Fig. 2 is a cross sectional view taken sub: stantially on a vertical plane passing through the axis of the grinding wheel spin-. dle; and

Fig. 3 is an enlarged detailed view showing the flexible driving connection between the pulley and grinding wheel spindle.

In accordance with the invention, a swing frame grinder is provided having a main frame 11 supported by any suitable meansv such as a flexible cable or chain 12 from an overhead support, thereby permitting free movement of the frame 11 in any direction. On one end of the frame 11 is mounted the wheel guard and housing 13 to support the grinding wheel 14. The grinding wheel 14 is mounted on the rotatable spindle 15 and adapted to be rotated by means of a pulley 16. On the other end of the frame 11 is mounted an electric motor 18 having a driving pulley 19 connected to rotate the pulleylG and consequently the grinding wheel 14 by means of a driving belt 20. To give the driving belt 20 the proper tension, any suitable construction is utilized such as an idler pulley 22 mounted on the swinging arm 23 which is pivotally mounted on the bracket 24. The bracket 2% is mounted on the main frame 11. This idler pulley may be of any suitable construction and of the proper weight and size to give the desired amount of tension to the driving belt.

To control the movement of the swing frame grinder to traverse the grinding wheel over the surface as desired, a pair of handles 25 are provided which are adapted to be gripped by the operator to move and swing the grinding wheel in any direction either vertically or horizontally.

To permit the swing frame to be readily balanced, any suitable construction may be utilized, but in the preferred construction a supporting nut 27 is mounted on an adj usta ble screw 28 which is rotatably supported in suitable bearings 29 and 30 on the frame 11. By turning the screw 28, the nut is moved longitudinally relative to the frame 11 so that the point of support or fulcrum of the swing frameis shifted to put the frame in balance longitudinally of the machine.

In the preferred construction, an adjustable mounting is provided to permit the use of any standard motor of varying size, so that the machine may be sold either with or without an electric motor attached. In the construction as illustrated in the drawings, a supporting plate 33 is rigidly mounted on the end of the frame 11 which in turn carries a slidably adjustable plate 8 1. The motor 18 is fastened to the adjustable plate 34 by bolts and may be adjusted laterally of the supporting plate 33 to balance the grinder laterally of the frame.

To attain one of the objects of the invention, any suitable yieldable or resilient mounting for the grinding wheel spindle may be utilized. In the preferred construction, however, the outer end of the spindle 15 is mounted in a bearing 40, which is yieldably or resiliently supported in the housing cover plate a1 by radially projecting studs 42. These studs are screw-threaded into the bearing and surrounded with springs 43 between the outer face of the housing 41 and thrust collars 14. These studs are provided with a threaded portion having nuts 45 so that the tension of the springs 43 may be varied to give the bearing 10 the desired flexibility.

To form a rigid driving connection between the motor and pulley so as not to interfere with the yieldably mounted grinding wheel spindle, the pulley 16 is preferably mounted on a bearing portion of the wheel housing 13 and the pulley is constructed in two parts so that the portion 16 may be aligned with the driving pulley on the motor after the motor has been balanced on the frame. The other end of the spindle 15 may be driven by any of the well-known flexible driving and supporting connections, but in the preferred construction a flexible disk connection, such as is well known in the art, is used, comprising the spaced flexible driving disks 55. The disks are connected at three equidistant points to the hubs or projecting portions 56 on the plate 57 by means of threaded studs 58 and y the nuts 59. The plate 57 is mounted on the inner portion of the pulley 16 by cap screws (50. The outer end of the grinding wheel spindle 15 is provided with a tapered port-"ion 63 onto which the driving member 65 is fitted. The radially projecting arms 66 of the driving member 65 are connected to the disks 55 at points equidistant from the studs 58.

The spindle 15 passes through a clearance hole or opening in the portion 50 of the housing or guard 13 or that it is free to move or yield as permitted by the radial springs which support the bearing at the other end of the spindle.

The outer portion of the pulley 16 is slidably mounted on the bushing portion 68 and keyed thereto by a key 69 so that the pulley may slide axially to align the pulley with the motor driven pulley after the motor has been adjusted to balance the apparatus. After the pulley 16 has been aligned it may be locked in position on the bushing 68 by means of a set screw 70.

To permit the grinding wheel to be readily changed, the wheel housing or guard 13 is preferably constructed in two parts. The housing 13 is rigidly fixed to the end of the frame 11 and the removable housing or cover 11 supporting the bearing 40 is locked or clam ped to the housing 51 by means of a plurality of clamping studs. The studs are provided with nuts 71 having tapered portions engaging correspondingly shaped openings in the plate 41 so that as the nuts are tight ened in place they align and clamp the plate and consequently the resilient bearing carried bv the plate in operative position.

It will be readily seen that by removing the nuts 71 the housing or guard cover 41 may be moved. axially removing the bearing 40 from its position on the wheel spindle 1 1. The grinding wheel may then be removed by unscrewing the locking nut and removing the outer flange. W hen the new wheel has been placed in position the guard cover 11 and bearing 10 may he slipped over the end of the spindle 15 and locked in its proper position by the nut 71.

In the operation of this swing frame grinder, the operator, upon mounting the motor 18, adjusts the slide 34 so that the frame is balanced against rotary motion relative to the main supporting frame. After this has been accomplished, he then adjusts the balancing screw 28 to move the fulcrum point or point of suspension relative to the frame and thereby completely balance the structure, so

that the operator does not have to support the apparatus but merely has to apply Sllfil".

cient force to the handles to move the grinding wheel frame in the desired direction.

If the grinding wheel is slightly out of balance when inserted in the machine, the yieldable or resilient bearing construction will cause the grinding wheel to be rotated iii about the center of the mass instead of the center of the shaft as an axis when the wheel is rotated, thereby reducing vibrations between the grinding wheel and the frame of the machine to a minimum. Experimental tests of this apparatus have shown that the use of this new bearing construction has reduced the wear of the grinding wheel from three or four cubic inches per pound of metal removed to one cubic inch of wear per pound of metal removed.

Having thus described the invention, what we claim as new and desire to secure by Letters Patent is:

1. A grinding apparatus comprising a frame, means for suspending the same to permit free movement thereof, a grinding wheel, bearings therefor, means resiliently supporting a bearing on one end of the frame which permits movement of the grinding wheel axis when the wheel, is out of balance, a motor on the other end of the frame, and driving connections between the motor and the wheel which serve to rotate the latter for any position thereof.

2. A grinding apparatus comprising a freely movable frame, means to support said frame, a motor mounted at one end of said frame, grinding wheel spindle mounted at the other end thereof, means to support one end of the spindle including a flexible driving connection thereto, a resiliently mounted bearing for the other end of said spindle to prevent transmission of vibration from the grinding wheel to said frame, and a grinding wheel mounted on the spindle between the driving connection thereto and the resiliently mounted bearing.

3. A grinding apparatus comprising a frame, means to mount the same centrally to permit the frame to swing in various directions, means including a motor mounted adjacent to one end of the frame, a grinding wheel mounted adjacent to the opposite end of the frame, a driving pulley, a bearing therefor rigidly mounted on the frame, connections between said motor and pulley, a spindle for the grinding wheel, a movable bearing therefor, yieldable means for supporting the movable bearing on the frame, and flexible driving connections between said pulley and the yieldably supported spindle.

at. A grinding apparatus comprising a frame, a motor mounted adjacent to one end thereof. grinding wheel mounted adjacent to the other end thereof, a supporting nut mounted centrally of the frame, and a screw for finely adjusting the position of the sup- 3 rt to balance the frame.

5. A grinding apparatus comprising a freely movable frame, means to adjustably fulcrum. said frame, a motor mounted at one end of said frame, a grinding wheel housing on the other end of said frame, a driving pulley rotatably mounted. on a portion of said housing, driving connections between said motor and pulley, a grinding wheel spindle rotatably mounted within said housing, means including flexible driving connections between said pulley and one end of the spindle to support and rotate it, and a yieldable bearing to support the other end of said spindle to prevent transmission of vibrations from the grinding wheel to the frame.

6. A grinding apparatus comprising a frame, a spindle, a grinding wheel mounted centrally thereof, a housing on the frame protectively cove *ing the wheel, one side of which is removable, resilient bearing for one end of the wheel spindle mounted in the housing, and yieldable bearings for the other end supported on said removable side of the housing, whereby removal of said side and bearings permits replacement of the wheel.

7. A grinding apparatus comprising a freely movable frame, a motor at one end thereof, grinding wheel spindle rotatably mounted on the other end, means including flexible driving connections between said motor and one end of the spindle to support and rotate it, a resiliently mounted bearing for the opposite end of the spindle, and a support for the resiliently mounted bearing iounted on the frame to permit ready removal of the bearing for replacement of the grinding wheel.

8. A grinding apparatus comprising a freely movable frame, means to adjustably fulcrum said frame, a motor at one end thereof. a grinding wheel housing at the other end thereof, a grinding wheel spindle within said housing, flexible driving connections etween said motor and one end of said spindle, a resiliently mounted bearing for the other end of the spindle, and a support for the resiliently mounted bearing which is removably mounted on the housing and permits ready replacement of the grinding whee.

9. A grinding machine of the swing frame type comprising a frame, 21! ns to fulcrum the frame from a support, a grinding wheel spindle mounted on the frame on one side of the fulcruming means, a motor mounted on the frame on the opposite side of the fulcrum ing means, bearings for the wheel spindle, a

from said pulley to one end of the grinding Wheel spindle, a movable bearing for the other end of the spindle, and a resilient supporton the irzune for said movable bearing.

Signed at Worcester, this 28th day of June HOWARD W. DUNBAR. ALBERT G. BELDEN. CARL G. FLYGARE. 

